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排序方式: 共有5270条查询结果,搜索用时 31 毫秒
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Lois Isaksen MD 《Academic emergency medicine》2015,22(9):1125-1126
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Comparison of 2-dimensional and 3-dimensional acquisition for 18F-FDG PET oncology studies performed on an LSO-based scanner. 总被引:1,自引:0,他引:1
Martin A Lodge Ramsey D Badawi Richard Gilbert Pablo E Dibos Bruce R Line 《Journal of nuclear medicine》2006,47(1):23-31
Three-dimensional (3D) PET acquisition has the potential to reduce image noise but the advantage of 3D PET for studies outside the brain has not been well established. To compare the performance of 2-dimensional (2D) and 3D acquisition for whole-body (18)F-FDG applications, a series of patient studies were performed using a lutetium oxyorthosilicate (LSO)-based tomograph. METHODS: Comparative 2D and 3D images were acquired for 27 oncology patients using an LSO-based tomograph. Data acquisition (350-650 keV, 6 ns) started 99 +/- 12 min (mean +/- SD) after injection of 624 +/- 76 MBq (18)F-FDG. Bias caused by tracer redistribution and decay was eliminated by acquiring dynamic data over a single-bed position using a protocol that alternated between septa-in and septa-out modes (2D, 3D, 2D, 3D, 2D, 3D). Frames were combined to form 8 statistically independent sinograms: four 2D replicates (105 s) and four 3D replicates (90 s). The different frame durations in 2D and 3D compensated for the different number of overlapping bed positions required for an 85-cm whole-body study. Images were reconstructed with either 2D or fully 3D ordered-subsets expectation maximization (2 iterations and 8 subsets; 2D 6-mm gaussian, 3D 5- and 6-mm gaussian). Image target-to-background ratio was assessed by dividing the lesion maximum by the mean within a neighboring background region. Image noise was assessed by applying background regions of interest to the replicate images and calculating the within-patient coefficient of variation. RESULTS: The difference in target-to-background ratio between the 2D and 3D images, when they were filtered with 6-mm and 5-mm gaussian filters, respectively, was not highly statistically significant (P = 0.16). The mean ratio of 3D to 2D image values was 0.94 with 95% limits of agreement of 0.63-1.41. The within-patient coefficients of variation for the 2D and 3D images were 13% +/- 15% and 9% +/- 10%, respectively (P = 0.0005). CONCLUSION: Under conditions of matched target to-to-background ratios, the 3D mode was found to produce images with significantly less variability than the 2D mode. These data provide support for the use of 3D acquisition with LSO detectors to reduce scan times in whole-body (18)F-FDG applications. 相似文献
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Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
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Lois J.Pround 《中华内分泌代谢杂志》2006,22(4):i0011-i0012
血糖仪的调码是指不同批号的试纸由于生产条件的不同而产生的批间差异,因此,在使用不同批号的试纸测试血糖时,需要血糖仪根据试纸上的密码校准批间差异。目前市场上的血糖仪大多在更换试纸时必须先手动调整血糖仪的代码或手动插入试纸盒内专用的代码卡。 相似文献
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腕管综合征主要症状体征敏感性与特异性的比较 总被引:5,自引:1,他引:4
目的 比较腕管综合征 (carpaltunnelsyndrome ,CTS)主要症状、体征的敏感性与特异性。方法 对 10 1例 ( 162只手 )进行症状严重程度与功能状况的询问 ,感觉、运动功能的检查 ;其中 62只手在术后 6周再次测定。结果 162只患手中 15 8只具有典型症状 ( 98% )。Phalen征、前臂正中神经加压征、Semmes Weinstein单丝纤维测试阳性率分别为 98%、96%、82 %。 87%的患手出现肌力下降 ,拇短展肌肌力测定 (定量法 )结果显示 ,与徒手法相比 ,不同性别间、术前与术后的差异均具非常显著意义 (P <0 .0 1)。结论 典型症状、Phalen征、前臂正中神经加压征、拇短展肌肌力变化的敏感性与特异性最高 ,拇短展肌肌力定量法测定是判断腕管综合征严重程度、评定疗效的一个良好的客观指标。 相似文献
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Nina Singh Cheryl Wannstedt Lois Keyes Marilyn M Wagener Thomas V Cacciarelli 《Liver transplantation》2005,11(6):700-704
A vast majority of the transplant recipients are cytomegalovirus (CMV)-seropositive (R+). We sought to assess variables predictive of CMV infection, specifically in R+ liver transplant recipients. Study patients comprised 182 consecutive liver transplant recipients who survived at least 14 days after transplantation. Surveillance testing was used to detect CMV infection. Pre-emptive therapy was employed for the prevention of CMV disease, however, no antiviral prophylaxis was used for CMV infection. CMV infection developed in 32.5% (38 of 117) of R+ patients, 84.6% (33 of 39) of R-/D+, and 3.8% (1 of 26) of R-/D- patients. In R+ patients, Hispanic race (21.6% vs. 7.8%, P = 0.06), donor CMV seropositivity (73.7% vs. 45.6%, P = 0.005), and hepatocellular carcinoma (23.7% vs. 6.3%, P = 0.05) correlated with a higher risk of CMV infection. In a multivariate model, Hispanic race (OR: 3.5, 95% CI: 1.03-11.6, P = 0.045), donor CMV serostatus (OR: 4.0, 95% CI: 1.6-10.2, P = 0.003) and hepatocellular carcinoma (OR: 5.8, 95% CI: 1.6-20.5, P = 0.006) were all significant independent predictors of CMV infection. The aforementioned variables did not portend a higher risk of CMV infection in R-/D+ patients; donor CMV seropositivity overwhelmed all other risk factors in R- patients (P < 0.00001). In conclusion, CMV-seropositive liver transplant recipients at risk for CMV infection can be identified based on readily assessable variables. Preventive strategies may be selectively targeted toward these patients. 相似文献